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Theoretical Investigation of the Structural and Electronic Properties of Ionic Liquids and Their Adsorption on Graphene and Boron-Nitride Surfaces; Synthesis of α-Aminophosphonates Using Fe3O4 Magnetic Nanoparticles
, Ph.D. Dissertation Sharif University of Technology ; Fattahi, Alireza (Supervisor) ; Mahmoodi Hashemi, Mohammad (Supervisor)
Abstract
This thesis is divided into three parts: In part I, structure and electronic properties of ionic liquids based on N7, N9-dimethylguaninium cation and α-amino acid (Gly, His, Phe, Try, and Tyr) anions and also ionic liquids based on 1-ethyl-3-methylimidazolium [emim]+ cation and alkyl-trifluoroborate ([RBF3]-, R=n-CmH2m+1 (m=1-5)) anions were discussed at the DFT(B3LYP)/6-311++G(d,p) level of theory. Then, the effect of chain length in anion on the nature and strength of interaction between cation and anion was investigated. Our results indicated that interaction energy values decrease with the increase in side chain size in anion. NBO and QTAIM results indicated that the interaction in these...
Theoretical investigation on the structural and electronic properties of complexes formed by thymine and 2'-deoxythymidine with different anions
, Article Structural Chemistry ; Volume 23, Issue 1 , July , 2012 , Pages 17-28 ; 10400400 (ISSN) ; Fattahi, A ; Sharif University of Technology
2012
Abstract
Hydrogen bonding interactions between thymine nucleobase and 2'-deoxythymidine nucleoside (dT) with some biological anions such as F - (fluoride), Cl - (chloride), OH - (hydroxide), and NO 3 - (nitrate) have been explored theoretically. In this study, complexes have been studied by density functional theory (B3LYP method and 6-311++G (d,p) basis set). The relevant geometries, energies, and characteristics of hydrogen bonds (H-bonds) have been systematically investigated. There is a correlation between interaction energy and proton affinity for complexes of thymine nucleobase. The nature of all the interactions has been analyzed by means of the natural bonding orbital (NBO) and quantum theory...
Influence of cation-heteroatom (Li+, Na+, and K +) interaction on the structural and thermochemical properties of 2′-deoxythymidine nucleoside: Qtaim and NBO analyzes
, Article Journal of Theoretical and Computational Chemistry ; Volume 12, Issue 2 , December , 2013 ; 02196336 (ISSN) ; Fattahi, A ; Sharif University of Technology
2013
Abstract
Density functional theory (DFT) method and B3LYP/6-311++G(d,p) basis set were used to determine coordination geometries, binding strength, and metal ion affinity (MIA) for interaction of 2′-deoxythymidine (dT) with alkali metal cations including Li+, Na+, and K+. Calculations demonstrated that the interaction of dT with these cations is tri-coordinated η (O2, O4′, O5′). Among these cations, Li + cation exhibited the most tendency for interaction with dT. Cations via their interaction with dT can affect the N-glycosidic bond length, the values of pseudorotation of the sugar ring, the orientation of base unit with respect to sugar ring and the acidity of O5′H, O3′H, and N3H groups in 2′-dT...
Interaction of cations with 2′-deoxythymidine nucleoside and analysis of the nature and strength of cation bonds
, Article Journal of Physical Organic Chemistry ; Volume 25, Issue 2 , JAN , 2012 , Pages 153-161 ; 08943230 (ISSN) ; Fattahi, A ; Jamshidi, Z ; Sharif University of Technology
2012
Abstract
Binding of Mg 2+, Ca 2+, Zn 2+, and Cu + metal ions with 2′-deoxythymidine (dT) nucleoside was studied using a density functional theory method and a 6-311++G(d,p) basis set. This work demonstrated that the interaction of dT with these cations is tri-coordinated · (O2, O4′, O5′). Among the four types of cations, Zn 2+ cation exhibited the most tendency to interact with the dT. Cations via their interaction with dT can affect the N-glycosidic bond length, the values of pseudorotation of the sugar ring, the orientation of the base unit with respect to the sugar ring, and the acidity of the O5′H, O3′H, and N3H groups in the dT nucleoside. Natural bond orbital analysis was performed to calculate...
Ionic liquid based on α-amino acid anion and N7,N9-dimethylguaninium cation ([dMG][AA]): Theoretical study on the structure and electronic properties
, Article Journal of Physical Chemistry A ; Volume 116, Issue 22 , April , 2012 , Pages 5436-5444 ; 10895639 (ISSN) ; Fattahi, A ; Bayat, A ; Sharif University of Technology
2012
Abstract
The interactions between five amino acid based anions ([AA] - (AA = Gly, Phe, His, Try, and Tyr)) and N7,N9-dimethylguaninium cation ([dMG] +) have been investigated by the hybrid density functional theory method B3LYP together with the basis set 6-311++G(d,p). The calculated interaction energy was found to decrease in magnitude with increasing side-chain length in the amino acid anion. The interaction between the [dMG] + cation and [AA] - anion in the most stable configurations of ion pairs is a hydrogen bonding interaction. These hydrogen bonds (H bonds) were analyzed by the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis. Finally, several correlations...
Effect of mono-vacant defects on the opto-electronic properties of ionic liquid functionalized hexagonal boron-nitride nanosheets
, Article Journal of Molecular Liquids ; Volume 249 , 2018 , Pages 1172-1182 ; 01677322 (ISSN) ; Bayat, A ; Kamath, G ; Sharif University of Technology
2018
Abstract
We compare and contrast the physisorption behavior of imidazolium and butyltrimethylammonium based ionic liquids (ILs) on mono-vacant nitrogen and boron defective hexagonal boron nitride nanoflakes (h-BNNF) using M06-2X/cc-pVDZ level of theory. The presence of defects on the nanoflakes results in an increase in IL binding energy by ~ 1–27 kcal/mol partly due to the lowering of the energy band in the defective nanoflakes. Imidazolium based ILs adsorb energetically more favorably on h-BNNF-VB than on h-BNNF-VN while butyltrimethylammonium based ILs prefer to adsorb on h-BNNF-VN. Upon adsorption of imidazolium ILs on the nanoflakes, an increase in both HOMO and LUMO orbital energies is observed...
Design of silica supported task-specific ionic liquid catalyst system for oxidation of cyclohexene to adipic acid with 30% H 2O 2
, Article Catalysis Communications ; Volume 26 , September , 2012 , Pages 54-57 ; 15667367 (ISSN) ; Hashemi, M. M ; Shakourian Fard, M ; Sharif University of Technology
Elsevier
2012
Abstract
1-Butyl-3-methylimidazolium tungstate ([BMIm] 2WO 4) ionic liquid supported onto silica sulphamic acid demonstrated desirable performance for oxidation of cyclohexene to adipic acid. Simple experimental procedure, easy product isolation, catalyst recovery and reusability are some attractive features of this protocol
What roles do boron substitutions play in structural, tautomeric, base pairing and electronic properties of uracil? NBO & AIM analysis
, Article Journal of Physical Organic Chemistry ; Volume 25, Issue 9 , 2012 , Pages 787-796 ; 08943230 (ISSN) ; Abedin, A ; Shakourian Fard, M ; Fattahi, A ; Sharif University of Technology
Wiley
2012
Abstract
The synthesis of modified versions of deoxyribonucleic acid is an area that is receiving much attention. The replacement of the nitrogen atom on the nucleobases with boron atom has provided insight into deoxyribonucleic acid and ribonucleic acid stability, recognition, and replication at the atomic level. In the present research, we investigated a detailed density functional theory study of the structural, tautomeric, base-pairing ability, bond dissociation energy, and electronic properties of two boron analogues (i.e., boron substitutions at 4-position and 5-position of uracil) of uracil nucleobase. The effects of these modifications on theirs acid-base properties have been considered. Our...
Structural and electronic properties of alkyl-trifluoroborate based ionic liquids: A theoretical study
, Article Journal of Fluorine Chemistry ; Volume 153 , September , 2013 , Pages 96-100 ; 00221139 (ISSN) ; Jamshidi, Z ; Bayat, A ; Fattahi, A ; Sharif University of Technology
2013
Abstract
In this study, ionic liquids formed between 1-ethyl-3-methylimidazolium cation ([emim]+) and alkyltrifluoroborate ([RBF3]-, R = n-CmH2m+1 (m = 1-5)) anions have been investigated theoretically. The interactions between the cation and anions have also been calculated at the MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p) level of theory. The calculated interaction energies were found to decrease in magnitude with the increase of side-chain length in anions. The results of energy decomposition analysis (EDA) show that the interaction of these anions with [emim]+ cation is electrostatic in the nature and the side chain length in the anions has an important effect on the contribution of ΔEelect term. The...
Influence of the water molecules (n 5 1-6) on the interaction between Li +, Na +, K + cations and indole molecule as tryptophan amino acid residue
, Article Structural Chemistry ; Volume 23, Issue 3 , 2012 , Pages 857-865 ; 10400400 (ISSN) ; Nasiri, M ; Fattahi, A ; Vafaeezadeh, M ; Sharif University of Technology
2012
Abstract
Influence of the addition of water molecules (n = 1-6) on the interaction energy between Li +, Na +, K + cations and indole molecule as tryptophan amino acid residue is considered at MP2(FULL)/6-311++G(d, p)//B3LYP/6-311++G(d,p) levels of theory. The calculations suggest that the size of cation and the number of water molecules are two important factors that affect the interaction energy between the hydrated metal cation and indole molecule. The strength of cation-π interactions get substantially reduced when the metal ion is solvated or the size of metal cation increases. Quantum theory of atoms in molecules analysis of cation-π interaction indicates that there is a correlation between the...
Meta hybrid density functional theory study of adsorption of imidazolium and ammonium based ionic liquids on graphene sheet
, Article Journal of Physical Chemistry C ; Volume 119, Issue 13 , March , 2015 , Pages 7095-7108 ; 19327447 (ISSN) ; Jamshidi, Z ; Bayat, A ; Kamath, G ; Sharif University of Technology
American Chemical Society
2015
Abstract
In this study, two types of ionic liquids (ILs) based on 1 butyl 3 methylimidazolium [Bmim]+ and butyltrimethylammonium [Btma]+ cations, paired to tetrafluoroborate [BF4], hexafluorophosphate [PF6], dicyanamide [DCA], and bis(trifluoromethylsilfonyl)imide [Tf2N] anions, were chosen as adsorbates to investigate the influence of cation and anion type on the adsorption of ILs on the graphene surface. The adsorption process on the graphene surface (circumcoronene) was studied using M06 2X/cc pVDZ level of theory. Empirical dispersion correction (D3) was also added to the M06 2X functional to investigate the effects of dispersion on the binding energy values. The graphene···IL configurations,...
DFT study of the interaction of thymine with Cu+ and Zn 2+
, Article Scientia Iranica ; Volume 16, Issue 2 C , 2009 , Pages 75-80 ; 10263098 (ISSN) ; Fattahi, A ; Sharif University of Technology
2009
Abstract
Interaction of the DNA thymine base with Cu+ and Zn3+ was studied to explore: a) The metal binding energy (MIA) of thymine with Cu+ and Zn2+ and b) The possible correlation between charge transfer and MIAs. The gas-phase Cu+ and Zn2+ affinities of thymine, as well as the Mulliken charges, on the complexed metal cations were both determined at the same computational level, including the density functional level and employing the hybrid B3LYP exchange correlation potential in connection with the 6-311++G (d,p) basis set. All the molecular complexes were obtained by interaction between the most stable tautomer of thymine and two transition mono and divalent (Cu+, Zn2+) metal ions. To probe all...
Loss Management in Smart Distribution Systems
, Ph.D. Dissertation Sharif University of Technology ; Ehsan, Mehdi (Supervisor)
Abstract
One of the topics that has been given great consideration after restructuring and smart grid emergence, is loss management. This subject is specifically important in distribution systems, which have been reported to have 70% of the total loss in power systems. In this thesis, distribution loss is studied and its affecting factors are analyzed. Then loss optimization and loss cost allocation to distribution consumers are studeid. In order to acheive these two goals, it is neccessary for the distribution system to have the capabilities of a smart grid. The subjectof distribution reconfiguration is duiscussed as one of the loss reduction methods. Traditional reconfiguration problem trend...
Synthesis of α-aminophosphonates in the presence of a magnetic recyclable Fe3O4@SiO2-2mimSO3H nanocatalyst
, Article Bulletin of the Chemical Society of Japan ; Vol. 87, issue. 9 , 2014 , pp. 982-987 ; ISSN: 00092673 ; Rezayan, A. H ; Kheirjou, S ; Bayat, A ; Hashemi, M. M ; Sharif University of Technology
2014
Abstract
A highly efficient magnetic Brønsted acid catalyst was synthesized based on immobilization of 2-methylimidazole functionalized by chlorosulfonic acid on the surface of silica-coated magnetic nanoparticles (Fe3O4@SiO2-2mimSO3H). The catalyst has an excellent activity and recyclable for at least 6 reaction runs and is proven to be highly effective in the synthes is of α-aminophosphonate compounds in a green way. The facile recovery of the catalyst is carried out by applying an external magnet device. It is both "green" and efficient. The catalyst was fully characterized by techniques of TEM, SEM, FT-IR, TGA, and elemental analysis (CHNS)
Selective aqueous oxidation of alcohols catalyzed by copper (II) phthalocyanine nanoparticles
, Article Comptes Rendus Chimie ; Volume 19, Issue 3 , 2016 , Pages 313-318 ; 16310748 (ISSN) ; Kheirjou, R ; Rezayan, A. H ; Shakourian Fard, M ; Mahmoudi Hashemi, M ; Sharif University of Technology
Elsevier Masson SAS
2016
Abstract
A new catalyst based on metallophthalocyanine nanoparticles has been synthesized and characterized by scanning electron microscopy (SEM). The aqueous oxidation of alcohols to the corresponding carbonyl compounds (aldehydes and ketones) has been studied using tetra-n-butyl-ammonium-peroxo-monosulfate (n-Bu4NHSO5) as an oxidant and a catalytic system consisting of copper (II) phthalocyanine nanoparticles in water. The highly selective oxidation gave excellent yields of related aldehydes or ketones without remarkable over-oxidation of the carboxylic acids. Organic co-solvents, surfactants, and co-catalysts were not used in this catalytic strategy. This strategy was green and time effective. The...
Scheduling for Participation of a Virtual Power Plant in Energy and Reserve Markets Considering Renewable Energy Sources
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Ehsan, Mehdi (Supervisor)
Abstract
The appearance of renewable sources has created a more diverse energy mix and has made it challenging for grid operators to maintain stability in energy systems. The concept of a virtual power plant is the integration of different energy sources into a single entity that is collected and controlled through a central energy management system. It enables these sources to participate in electricity markets. This research presents a framework for the participation of a virtual power plant (VPP) in day-ahead (DA), reserve, and real-time (RT) energy markets. VPPs face several uncertainties, such as wind turbine (WT) production, demand, the status of calling the reserve, and energy market prices....
Design and Fabrication of Inductive High Temperature Superconducting Fault Current Limiter
,
Ph.D. Dissertation
Sharif University of Technology
;
Vakilian, Mehdi
(Supervisor)
;
Fardmanesh, Mehdi
(Supervisor)
Abstract
The continuous rise in electricity demand and the ever growing power generation in different power networks over the world have caused the short circuit level in the power systems to exceed the operational rating of the installed power devices (including cables, circuit breakers and buses). Replacing these devices with new higher rating devices is an expensive solution. From this point of view, utilizing fault current limiters is an economical solution. Superconducting fault current limiters form an efficient category of current limiters. This type is expected to be studied and used widely in future due to their advantages. In this thesis, the first chapter reviews the superconductivity...
Fuzzy reliability optimization models for redundant systems [electronic resource]
, Article International Journal of Industrial engineering ; July 2008, Vol. 4, No. 7, 1-9 ; Eshghi, Kourosh ; Eshraghniaye Jahromi, Abdolhamid ; Sharif University of Technology
Abstract
In this paper, a special class of redundancy optimization problem with fuzzy random variables is presented. In this model, fuzzy random lifetimes are considered as basic parameters and the Er-expected of system lifetime is used as a major type of system performance. Then a redundancy optimization problem is formulated as a binary integer programming model. Furthermore, illustrative numerical examples are also given to clarify the methods discussed in this paper
Shared information in a serial inventory system [electronic resource]
, Article International Journal of Advanced Operations Management - IJAOM ; 2011 Vol.3, No.2 pp.101 - 121 ; Eshraghniaye Jahromi, Abdolhamid ; Eshghi, Kourosh ; Sharif University of Technology
Abstract
In this study, a supply chain model consisting of a single product, one supplier and one retailer is considered. Transportation times are constant and demands at the retailer are assumed to be generated by a stationary Poisson process. Demands not covered immediately from inventory are backordered. The retailer carries inventory and replenishes stock according to a (Q, R) policy. The supplier has online information about the demand at the retailer and uses this information to replenish its stock. The order size at the supplier is a multiple integer to the retailer's order size. Considering order costs for the retailer and the supplier, we derive the exact cost function for this inventory...